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  1. Member
    Join Date: Aug 2014
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    Hey, so I recorded a rock concert on a beach in Egypt, and had to set my record volume realllllly low to get clean sound. The next day, I filmed some random stuff, but I had no idea that using the automatic mode on the camera (a Canon XL1) doesn't override the audio level setting, so I'm left with very low volume on those clips.
    I'm aware that I can just turn it up in a video editing, but with a poor signal/noise ratio. But, is there a better way? I'm sure the self-noise from the motor holds fairly steady. Can I use part of the recording with no sound (except noise) to analyze and remove the noise in the rest? I think you could do that sort of thing way back with Nero wave editor. I downloaded audacity...is there a tool in that that might help?
    I have only listened to the audio through headphones plugged into the camera. I haven't actually tried boosting them on the computer to see how much noise I'll be dealing with.
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  2. Member MOVIEGEEK's Avatar
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    Audacity can do it but as mentioned the background noise will also be boosted, maybe post a short clip of the audio so we can have a go at it.
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  3. Member
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    Originally Posted by MOVIEGEEK View Post
    Audacity can do it but as mentioned the background noise will also be boosted, maybe post a short clip of the audio so we can have a go at it.
    Yeah, I suppose I should at least listen to it first. Maybe I can turn it up and it will be acceptable. I'll post it ASAP
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  4. Can I use part of the recording with no sound (except noise) to analyze and remove the noise in the rest?
    Perhaps like this

    https://www.youtube.com/watch?v=mlKX6p85R2M
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  5. Member
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    Originally Posted by videobruger View Post
    Can I use part of the recording with no sound (except noise) to analyze and remove the noise in the rest?
    Perhaps like this

    https://www.youtube.com/watch?v=mlKX6p85R2M
    Yeah. That's the one. I'll give it a try.
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  6. For Audacity: In case you don't already have you'll probably want to install Lame/FFmpeg
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  7. Member
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    Sorry, I got sidetracked with other projects. I'll upload a clip of the original audio, a copy of the clip I've worked on in Audacity, and one Ive worked on in Nero wave editor. (Though the new version sucks. I had a really old version that had much better noise reduction and band extrapolation)
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  8. Member
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    Okay, I just uploaded two clips here. I was able to do quite a bit to remove the noise. In the end, I used Nero to remove as much noise as possible, then Audacity to compress it and bring the level up. Then I gave the audacity noise reduction a go (I'd already used it on its own and it was nowhere near as good as the Nero one, but it worked well after I'd already used the one in Nero for some reason) Then I compressed it again, though, I should probably have just normalized it at that point. I managed to get rid of most of the noise at the cost of some clarity. I might go back to Nero and see if they still have the old band extrapolation tool I used to use on copies of cassette audio books

    Oh, how do I post the files here? I uploaded them, but when I click the button to get the link, a download window appears
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  9. Originally Posted by micklos View Post
    Oh, how do I post the files here? I uploaded them, but when I click the button to get the link, a download window appears
    Right click on the link and copy it (Copy Link Location, Copy Shortcut, whatever your browser calls it). Then paste it into a post.
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  10. Or use the "Upload files/Manage attachements" button below your post.
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  11. Member
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    Thanks. Here's the original. I guess it sounds as you'd imagine a recording of someone speaking would sound if the camera had been set for recording a rock concert, as was the case.
    http://files.videohelp.com/u/232887/Original.wav

    Here's my first attempt at cleaning it. I forgot to write my settings down, but once I'm happy that I've done all I can, I'll just apply them to everything.
    http://files.videohelp.com/u/232887/Enhanced.wav

    I split the contents of the tape scene by scene in case I need to treat each separately, but I probably wont. The noise is just static, motor-noise, tape hiss, etc, and fairly constant.
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  12. Member
    Join Date: Jan 2014
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    Give wavecor.co.uk/ a try for the audio component.It has done an excellent job on my antique 78's and LP's.David is extremely helpful.
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  13. Member
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    Thanks. I'll have a look, but I'd rather use software I already have here, first.
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  14. Use a high pass filter to reduce the wind buffeting noise, 12 dB/octave, 150 Hz cutoff. Then use a low pass filter to eliminate the highest hiss, 12 dB/octave, 8000 Hz. Then sample the noise and reduce it by 10 to 25 dB or so. Unfortunately, the more you reduce the noise the more artifacts you get. So it's a balancing act. I usually stay in the 10 to 15 dB range. Oh, and amplify the signal by about 15 dB. You might even consider dropping the left channel and working in mono.
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  15. Member
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    Originally Posted by jagabo View Post
    Use a high pass filter to reduce the wind buffeting noise, 12 dB/octave, 150 Hz cutoff. Then use a low pass filter to eliminate the highest hiss, 12 dB/octave, 8000 Hz. Then sample the noise and reduce it by 10 to 25 dB or so. Unfortunately, the more you reduce the noise the more artifacts you get. So it's a balancing act. I usually stay in the 10 to 15 dB range. Oh, and amplify the signal by about 15 dB. You might even consider dropping the left channel and working in mono.
    Amplify before or after the other stuff? Thanks. I'm not very familiar with audacity, so I'll give that a try and see how it compares to my first attempt
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  16. Member
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    I think the editable noise curve dealie in Nero does a better job with the noise, but working in mono is definitely a good idea. I noticed in Audacity that I could use more aggressive noise reduction settings on one channel. And the left channel is consistently better on all of the clips. The band pass filters worked quite well, so I'm going to have a shootout between those and the ones in Nero wave editor. Between the two programs, I should be able to find something.
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  17. Amplify part way before the high pass filter (so the amplified wind buffeting doesn't blow out the voice and other sounds you want to keep) then more after.
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  18. Member
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    I'll try that next. Here's the latest effort. I think I should allow a bit more noise through to keep that robotic sound down. http://files.videohelp.com/u/232887/Enhanced%202.wav
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  19. Here's what I got with a little more fiddling.
    Attached Files
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  20. Member
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    Originally Posted by jagabo View Post
    Here's what I got with a little more fiddling.
    Awesome. I think that's as good as it's going to get. Did you do that from the original, or from one of the ones I've been screwing with?
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  21. That was from the original. I ran a sequence similar to the one I posted earlier. But I changed the cutoffs and slopes a bit. I think the sequence was:

    process with 32 bit floats
    Split stereo tracks
    Delete left track
    Make right track mono
    Amplify +10 dB
    HighPass 150 Hz, 24 DB/octave
    LowPass 6000 Hz, 36 dB/octave
    Train noise reducer with silent (except for noise) portion
    Noise reduction 20 dB
    Amplify +10 dB.
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  22. Member
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    Originally Posted by jagabo View Post
    That was from the original. I ran a sequence similar to the one I posted earlier. But I changed the cutoffs and slopes a bit. I think the sequence was:

    process with 32 bit floats
    Split stereo tracks
    Delete left track
    Make right track mono
    Amplify +10 dB
    HighPass 150 Hz, 24 DB/octave
    LowPass 6000 Hz, 36 dB/octave
    Train noise reducer with silent (except for noise) portion
    Noise reduction 20 dB
    Amplify +10 dB.
    Are you sure you used the right track? I think the left had less noise. The right had a few loud clicks, too.
    Anyway, that looks pretty simple except..."process with 32 bit floats" I have no idea what that means. I've not used audacity much at all.
    What were the other settings on the noise reduction? The sensitivity, tonal smoothing and whatever the other one was?

    The crazy thing is: My audio was screwed because I'd set it for a rock concert the night before, BUT the levels crept up after soundcheck, so I got distorted audio on that! No fixing that. I never figured why the meter on the XL cameras isn't back-lit.
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  23. Yes, I used the right channel. It had more loud pops but it had a better signal to noise ratio. ie, more signal, less noise (aside from the pops). For 32 bit floats use the pulldown next to the file name at the left of the track:

    Name:  float.png
Views: 36
Size:  26.2 KB
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  24. Member
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    [QUOTE=jagabo;2363115]Yes, I used the right channel. It had more loud pops but it had a better signal to noise ratio. ie, more signal, less noise (aside from the pops). For 32 bit floats use the pulldown next to the file name at the left of the track:

    You, sir, are a legend. Thanks. The pops are no problem. If I remember they are only right at the start, in a part I won't be using. It's odd that the right channel is better. I wonder if the mic was attached upside down...it makes more sense for the Left to be better, since the camera was on my right shoulder.

    Lastly...the other settings on the noise reduction...were they default? I never played with them because it's not obvious what they mean except for response time, or whatever.
    Anyway, that sounds plenty good enough for a Youtube video. If only there was something that could be done about the distortion on the concert!
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  25. I left the other noise reduction settings at their defaults. I'd suggest you play with them (and all the other settings I used) to tune the audio to your liking and each source.
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  26. Member
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    Originally Posted by jagabo View Post
    I left the other noise reduction settings at their defaults. I'd suggest you play with them (and all the other settings I used) to tune the audio to your liking and each source.
    Will do. A lot of that footage I was in the desert at the end of the runway so, at some point, there are going to be planes passing 50ft over my head. Not sure how I'm going to deal with that. I'll have to time a volume fade to match the planes approach, or just hope that there are no planes during any parts I want to keep
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